In computing, virtualization is defined as the creation of a virtual (rather than an actual) version of an entity such as an operating system, a server, a storage device or a network resource. Virtualization technology makes it possible to run multiple virtual “machines” on a single physical computer system, where each virtual machine executes its own instance of an operating system. Multiple virtual machines running on the same physical computer system typically require the ability to share input/output (I/O) devices such as storage devices (e.g., disk drives) and network adapters.
When concurrently executing multiple instances of an operating system via virtualization, a computer system typically virtualizes its physical storage devices. By implementing storage virtualization, each operating system instance accesses a corresponding unique instance of a virtual storage device, where all the virtual storage devices are sharing the same physical storage devices.